Convertible multi-stage / bi-caval femoral venous cannula

ABSTRACT

A venous drainage cannula, catheter, or other device is in certain embodiments convertible or adjustable for application in cardiac surgery procedures involving cardiopulmonary bypass. Such a convertible cannula device can be modified, for example, for use as both a multi-stage cannula and a bi-caval cannula, so that the same device can be used in multiple different procedures where one or the other cannula type is needed. Such convertible cannula or other device can simplify and reduce a number of parts needed for a bypass procedure, by providing one adjustable and versatile device to serve multiple functions where different cannulae are traditionally required. Various embodiments further provide cannula devices where a variety of different hole or opening arrangements and configurations can be achieved, to adapt to various different procedures.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/US2017/013645, filed Jan. 16, 2017, the entire disclosure whichin incorporated by reference.

BACKGROUND Field

The present application generally concerns venous cannulae, and morespecifically, to a venous drainage cannula or catheter that can beadjustable for application in various different cardiac surgeryprocedures involving cardiopulmonary bypass.

Description of Related Art

Various different surgical procedures are or can be performed usingcardiopulmonary bypass. Such “on-pump” cardiopulmonary bypass proceduresmay be necessary or favorable in situations where heart function must beinterrupted, while circulation must be continued in a patient. Forexample, in cardiac surgeries where the heart wall is opened to gainaccess to one or more chambers of the heart, cardiopulmonary bypass canbe used to temporarily replace the heart function and support bloodoxygenation and circulation, while the heart can be emptied of blood inorder to more easily facilitate the particular surgical procedure.

During a cardiopulmonary bypass, a pump or similar machine is connectedto the veins and arteries near the heart. Deoxygenated or venous bloodthat is returning to the heart is removed from the body by one or morecannulae or other devices. Generally, such cannulae are positioned inthe right atrium, in the superior vena cava and/or the inferior venacava, and/or further away from the heart, for example, in the femoralvein, to intercept the deoxygenated blood that would otherwise return tothe heart. Withdrawn blood is then oxygenated and further processed, andreturned to the body, for example, into the ascending aorta. In thismanner, a patient's body can remain oxygenated while, for example, acardiac procedure is being performed.

Traditionally, cardiopulmonary bypass surgery involves insertion of twoseparate venous cannula for separate blood withdrawal at the superiorvena cava and the inferior vena cava. To prevent blood from entering theheart during a cardiac surgical procedure, a first cannula is positionedin the superior vena cava, and a second cannula is positioned in theinferior vena cava. In some instances, both the superior and inferiorvenae cavae are then clamped or otherwise sealed from the right atrium.In this manner, blood is drained or withdrawn from the body by the twocannulae prior to reaching the heart.

Recently, more research and emphasis has been placed on less invasivesurgical procedures which involve, for example, a lower number of and/orsmaller incisions for performing the same procedures. In the field ofcardiac surgery, such procedural modifications may include reducingwound opening sizes and/or reducing the number of parts required at thesurgical site. For example, mini-sternotomy approaches to heart valverepair or replacement procedures, where only part of the sternum orbreastbone is split or separated to gain access to the heart, aregaining popularity in lieu of, for example, the same procedures where astandard sternotomy (i.e., where the entire sternum is separated) isperformed.

Since a mini-sternotomy may only yield an incision that may beapproximately half the length of an incision made in a standardsternotomy, there is a need or desire to reduce the number of surgicalparts and instruments which require access to the main incision site. Inrecent years, femoral venous cannula have gained popularity in suchprocedures. Femoral venous cannulae are inserted through the femoralvein at or near the groin or thigh area, away from the surgical field.The cannula is advanced through the femoral vein and up through theinferior vena cava towards the heart. The end region of a femoral venouscannula is generally long, with multiple stages of openings, and ispositioned to traverse the right atrium, with at least one set ofopenings positioned in the superior vena cava and one set of openingspositioned in the inferior vena cava to effect blood drainage. Such afemoral venous cannula can therefore replace the use of the two separatesingle stage cannula used in traditional cardiopulmonary bypassprocedures, and so reduces the total number of parts required for acardiopulmonary bypass, and may also reduce the number of incisions thatare required at the surgical site. Furthermore, since the access site ofthe femoral venous cannula is away from the surgical site (e.g., at thegroin or thigh), the use of femoral venous cannulae can also serve toreduce clutter or crowding at the surgical site.

Generally, different femoral venous cannulae are used for procedures onthe left and right sides of a heart, respectively. For example, foraortic valve or mitral valve replacement or repair, a multi-stagefemoral venous cannula may be utilized, where drainage is performed oneach of the superior vena cava, the inferior vena cava, and the rightatrium. The use of a multi-stage cannula for these procedures may bebeneficial, for example, for more effective blood drainage. Suchmulti-stage cannulae may include drainage openings along an entire endportion of the cannulae, for example, as seen in FIG. 1, so that theopenings can be simultaneously positioned in the superior vena cava, theright atrium, and the inferior vena cava.

However, for some procedures, surgical access to the right atrium, ormore generally to the right chambers of the heart, may be required, forexample, for tricuspid valve replacement or repair. In these situations,a bi-caval drainage approach may be more desirable, where drainageoccurs only at the superior vena cava and the inferior vena cava, butnot at the right atrium, so that the surgical procedure can be moreeasily performed there. Typically, a different bi-caval cannula may beused in these circumstances, where openings at the end portion of thecannula are interrupted by a central or middle portion that does notinclude any openings, for example, as seen in FIG. 2. Use of such abi-caval cannula can still drain blood at the superior and inferiorvenae cavae, while the right atrium is isolated for the surgicalprocedure.

SUMMARY

In some instances, multiple surgical procedures need to be made on asingle patient. For example, a patient may require replacement or repairof an aortic or mitral valve, as well as a separate procedure on atricuspid valve. Or more generally, a surgeon may need to performseparate procedures on the right and left sides of the heart of apatient. Previously, such situations involved the complete removal of afirst type of femoral venous cannula after completion of the firstprocedure, and insertion of a second type of femoral venous cannulabefore beginning the second procedure.

An object of the invention is to provide a femoral venous cannula devicethat is adjustable between a multi-stage cannula and a bi-caval cannula,for example, to reduce the number of parts needed for cardiopulmonarybypass surgery. Another object of the invention is to provide such anadjustable cannula, to add flexibility and simplify procedures insituations where different cannulae are traditionally required. Inaccordance with the objects of the invention, embodiments of theinvention provide a convertible femoral venous cannula that can bemodified to be used in both procedures requiring a multi-stage cannulaand procedures requiring a bi-caval cannula. Embodiments of theinvention further provide a femoral venous cannula where a variety ofdifferent hole or opening configurations can be achieved, to adapt tovarious different procedures.

According to one embodiment, a device for use in cardiopulmonary bypassincludes a cannula configured to be positioned in at least one of aright atrium, a superior vena cava, or an inferior vena cava of apatient, the cannula having a first end, a second end, and alongitudinal axis extending between the first end and the second end.The cannula includes a first section at the first end, the first sectionincluding an outer wall and having at least one opening therethrough, asecond section connected to the first section along the longitudinalaxis, the second section including an outer wall and having at least oneopening therethrough, and a third section connected to the secondsection along the longitudinal axis on a side of the second sectionopposite the first section, the third section including an outer walland having at least one opening therethrough. In a first configuration,the openings in each of the first section, the second section, and thethird section are respectively open to inner spaces defined by the firstsection, the second section, and the third section. In a secondconfiguration, the at least one opening in the second section isoccluded to restrict communication with the inner space defined by thesecond section, while the openings in the first section and the thirdsection remain open to the inner spaces defined by the first section andthe third section, respectively.

According to another embodiment, a method is provided for adjusting andpositioning a femoral venous cannula in a patient for cardiopulmonarybypass during a cardiac procedure. The cannula has a first end, a secondend, and a longitudinal axis extending between the first end and thesecond end, and includes a first section at the first end and includingan outer wall and having at least one opening therethrough, a secondsection connected to the first section along the longitudinal axis andincluding an outer wall and having at least one opening therethrough,and a third section connected to the second section along thelongitudinal axis on a side of the second section opposite the firstsection and including an outer wall and having at least one openingtherethrough. In a first configuration, the openings in each of thefirst section, the second section, and the third section arerespectively open to inner spaces defined by the first section, thesecond section, and the third section, while in a second configuration,the at least one opening in the second section is occluded to restrictcommunication with the inner space defined by the second section, whilethe openings in the first section and the third section remain open tothe inner spaces defined by the first section and the third section,respectively. The method includes adjusting the cannula to one of thefirst configuration or the second configuration, inserting the cannulathrough the femoral vein of the patient and advancing the cannulatowards the heart of the patient, and positioning the cannula at a firstposition in the patient wherein the at least one opening of the firstsection of the cannula is arranged in the superior vena cava, the atleast one opening of the second section of the cannula is arranged inthe right atrium, and the at least one opening of the third section ofthe cannula is arranged in the inferior vena cava.

Embodiments of the invention therefore provide a femoral venous cannuladevice that is convertible between a multi-stage cannula and a bi-cavalcannula for different surgical procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention willbecome apparent from the following detailed description of embodiments,by means of the accompanying drawings. In the drawings:

FIG. 1 shows a multi-stage femoral venous cannula;

FIG. 2 shows a bi-caval femoral venous cannula;

FIG. 3 shows a femoral venous cannula that is positioned at a heart fora cardiopulmonary bypass procedure according to an embodiment of theinvention;

FIG. 4 shows a femoral venous cannula configured as a multi-stagecannula according to a first embodiment of the invention;

FIG. 5 shows a cross-sectional view of the femoral venous cannula ofFIG. 4, where the cross section includes a longitudinal axis of thecannula;

FIGS. 6A and 6B show cross-sectional views of the femoral venous cannulaof FIG. 4 in a first position and a second position, respectively, thecross-section taken in a plane perpendicular to the longitudinal axis ofthe cannula;

FIG. 7 shows an enlarged view of an end the femoral venous cannula ofFIG. 4, where the cannula is configured as a bi-caval cannula;

FIGS. 8A and 8B show an enlarged view of a femoral venous cannulaaccording to a second embodiment of the invention, in a first positionand a second position, respectively;

FIGS. 9A and 9B show a multi-stage femoral venous cannula and a sleeve,respectively, according to a third embodiment of the invention; and

FIG. 10 shows the cannula and the sleeve in FIGS. 8A and 8B in anassembled state.

DETAILED DESCRIPTION

FIG. 3 shows a heart and a femoral venous cannula according to anembodiment of the invention. The right atrium 110 of the heart 100 isconnected to the inferior vena cava 111, which connects the veinslocated in the lower part of the patient's body to the heart 100, andthe superior vena cava 112, which connects the veins located in theupper part of the patient's body to the heart 100. Deoxygenated bloodgenerally empties from the inferior vena cava 111 and the superior venacava 112 into the right atrium 110, to be oxygenated and recirculatedthrough the body.

In FIG. 3, a femoral venous cannula 1 according to an embodiment of theinvention has been positioned through the inferior vena cava 111 and theright atrium 110, and protrudes into the superior vena cava 112. Thecannula 1 is positioned in this manner to drain the patient's body ofdeoxygenated blood, and to deliver the blood to, for example, acardiopulmonary bypass pump or machine, for oxygenation and furtherprocessing, before being returned to the patient's body.

As can be seen in FIGS. 3 and 4, the cannula 1 according to anembodiment of the invention has a first section 10 and a second section20. Each of the first and second sections 10, 20 may be substantiallycylindrical. The sections 10, 20 are flexible to ease insertion andpositioning in the body, and one or both sections 10, 20 may be wirereinforced. Each section 10, 20 includes at least one opening 11, andtypically a plurality of openings 11. The openings 11 in FIGS. 3 and 4are circular. The openings 11 in the first section 10 may be shapedand/or arranged substantially similarly to the openings 11 in the secondsection 20. In some embodiments, the openings 11 in the first section 10may have different shapes and/or spacing than the openings 11 in thesecond section 20, based on the particular clinical application and/orpatient characteristics. A distal end of the first section 10 of thecannula 1 may be tapered or otherwise shaped to further ease insertionof the cannula 1 through the body.

In the embodiment of FIGS. 3 and 4, the sections 10 and 20 are separatedby a third section 30, which include one or more openings 31, andgenerally a plurality of openings 31. The openings 31 in the embodimentin FIGS. 3 and 4 are illustrated as being square or rectangular shapedto be more easily distinguishable from the openings 11. However, inother embodiments, the openings 31 may be the same shape (e.g., round,similar to how openings 11 are illustrated in the figures), and have thesame spacing, as the openings 11 in either sections 10 or 20. Thesection 30 may be configured similarly to the sections 10 and 20. Thatis, the section 30 may also be substantially cylindrical, may beflexible, and/or may be wire-reinforced. In other embodiments, thesection 30 may be configured differently than the sections 10 and 20,for example, the section 30 may be made of a semi-rigid material that ismore rigid than a material used for the sections 10 and 20, and may notbe wire-reinforced.

The sections 10, 20, 30 may further be connected to an elongated tubularsection 40 that connects the cannula 1 to the outside of the patient,for example, first for facilitating insertion and positioning of thecannula 1, and later for connection to a cardiopulmonary bypass pump.

As can best be seen in FIG. 3, in a final position, the cannula 1according to the first embodiment is positioned so that the firstsection 10 is located in or approximate the superior vena cava 112, thesecond section 20 is located in or approximate the inferior vena cava111, and the central third section 30 is located in or approximate theright atrium 110 of the heart 100. Generally, a length of the centralsection 30 is sufficiently long to extend from the inferior vena cava111 to the superior vena cava 112, so that the holes 11 in sections 10and 20 are only positioned in the inferior and superior venae cavae 111,112, and not in the right atrium 110. In some instances, different sizedcannula with, for example, different widths or central sections 30having different lengths, may be available for selection, depending oncharacteristics of the patient. The cannula 1 can be inserted, forexample, via the femoral vein near the thigh or groin of the patient,and advanced towards the heart 100 through the inferior vena cava 111.In other embodiments, it may be possible to insert the cannula 1 in theopposite direction via the superior vena cava 112, or from anotheraccess point. In FIG. 3, the cannula 1 is configured as a multi-stagecannula, where the holes or openings 11 and 31 in each of the sections10, 20, and 30 are open and facilitate drainage of deoxygenated bloodfrom the body. The multi-stage cannula configuration illustrated inFIGS. 3 and 4 may be used, for example, during aortic or mitral valvereplacement or repair procedures.

Meanwhile, embodiments of the invention provide a convertible cannula,where the central section 30 of the cannula 1 can be adjusted so thatthe openings 31 are sealed shut instead of kept open, to effectivelyconvert the cannula 1 from a multi-stage cannula to a bi-caval cannula,so that the same cannula 1 can be used for different cardiac surgeriesand procedures which require either type of cannulation.

In the embodiment of FIGS. 3 and 4, section 30 of cannula 1 includes ashutter system. Referring to the cross-sections in FIGS. 5, 6A, and 6B(where FIGS. 6A and 6B shows cross-sections of section 30 of cannula 1in different positions or configurations, described in greater detailbelow), at the section 30, the cannula 1 may include an outer wall 32and an inner wall 34, where the inner wall 34 defines an inner lumen 12,and where a separate space is formed between the inner wall 34 and theouter wall 32. The inner lumen 12 may connect to the section 10 at thedistal end of the cannula 1, for example, for facilitating drainage fromthe openings 11 in section 10. The outer wall 32 defines the openings31, which extend through the outer wall 32 into a space between theinner wall 34 and the outer wall 32, to facilitate drainage by thecannula 1 through the openings 31. In some embodiments, the inner lumen12 may also communicate with the space between the inner wall 34 and theouter wall 32, or the inner wall 34 may be omitted, so that the openings11 and 31 open into a same space inside the cannula 1. The shuttersystem further includes at least one sliding wall 33 positioned along aninner surface of the outer wall 32. The sliding wall 33 may include aplurality of longitudinal strips that extend along a length of thesection 30 between the sections 10 and 20. Alternatively, the slidingwall 33 may be a substantially cylindrical wall that is slightly smallerin diameter or width than the outer wall 32, and that includes openingsthat are either substantially the same size or larger than the openings31.

In a first position, as illustrated in FIGS. 5 and 6A, the sliding wall33 is positioned so that the openings in the sliding wall 33 are alignedwith the openings 31 in the outer wall 32, so that the sliding wall 33does not block the openings 31 or obstruct access into the space betweenthe inner wall 34 and the outer wall 32. In a second position, asillustrated in FIGS. 6B and 7, the sliding wall 33 can be rotatedrelative to the outer wall 32 of section 30 so that the sliding wall 33occludes or blocks the openings 31, and thus blocks access into thecannula 1 from the openings 31, while the openings 11 of cannula 1remain open. Therefore, in the configuration shown in FIG. 7, thecannula 1 has been converted to function as a bi-caval cannula, wheredrainage occurs at the inferior and superior venae cavae 111, 112through sections 20, 10, but no longer occurs at the right atrium 110,since the openings 31 are now blocked. The bi-caval cannulaconfiguration illustrated in FIG. 7 may be used, for example, duringprocedures where access to the right chambers of the heart are required,such as during tricuspid repair or replacement, and/or where drainage atthe right atrium 110 may not be needed or desired, or may hinder orobstruct the particular procedure.

In the manner described above, the internal sliding wall 33 slides overthe holes 31 in section 30, effectively opening and closing the holes 31based on the requirements of the particular procedure. In oneembodiment, the shutter system in FIGS. 3-7 may be remotely activated,for example, through an electronic switch system that can be actuatedfrom outside the patient's body. In another embodiment, the sliding wall33 may be mechanically rotated, for example, via a lever or similarmechanism at or near the section 30 of the cannula, or for example, asimilar mechanism that connects to the outside of the patient's bodythrough the tubular section 40.

In a second embodiment, illustrated in FIGS. 8A and 8B, a centralsection 30′ of a cannula may instead include one or more sliding walls35 that move laterally or longitudinally along the length of thecannula, rather than rotate relative to the rest of the cannula. Thesliding wall 35 in FIGS. 8A and 8B may include, for example, a series ofring-shaped strips that are slightly smaller in diameter or width thanthe outer wall 32, or may include one substantially cylindrical wallthat has openings substantially the same size or larger than theopenings 31. As discussed above, actuation of the sliding wall 35 movesthe wall 35 longitudinally, either towards the section 10 or towards thesection 20, so that the sliding wall 35 occludes the openings 31, as canbe best seen in FIG. 8B. The other portions of the cannula in FIGS. 8Aand 8B may be similar to those discussed with respect to FIGS. 3-7.

Various modifications can also be made to the embodiments of the femoralvenous cannula 1 in FIGS. 3-7 and in FIGS. 8A-8B. For example, in theembodiments discussed above, the sliding shutter walls 33, 35 arelocated along an inner surface of outer wall 32. However, in someembodiments, the sliding walls 33, 35 can be positioned on the outsideof the cannula, or can be tightly sandwiched between two layers of thesection 30. Furthermore, the sections 30, 30′ and/or the sliding shutterwall 33, 35 are described as being semi-rigid and made of a stiffermaterial than a material of the sections 10 and 20, but in someembodiments, the sections 30, 30′ and/or the sliding shutter wall 33, 35may be constructed similarly to the sections 10, 20, and can also bewire-reinforced. Various other modifications can also be made to thedescribed embodiments without departing from the general scope of theinvention.

A third embodiment of the invention is illustrated in FIGS. 9A, 9B, and10. In the third embodiment of the invention, a kit including a cannula2 and an elastic tube or covering sheath 3 are provided. The cannula 2can be, for example, a general multi-stage femoral venous cannula, suchas the multi-stage cannula illustrated in FIG. 1. The cannula caninclude a plurality of holes or openings 11 along the length of thecannula 2, which are spaced apart and extend sufficiently along a lengthof the cannula 2 for the openings 11 to be positionable in the rightatrium 110, the inferior vena cava 111, and the superior vena cava 112of a patient simultaneously.

The elastic sheath or tube 3 is generally constructed of a material soas to be impermeable to blood. Furthermore, the tube 3 may include, forexample, an adhesive 4 that is applied along the ends of the tube 3 (asillustrated), or alternatively, along an entire inner surface of thetube 3. The adhesive 4 provided will generally be strong enough to allowthe tube 3 to permanently adhere to the cannula 2. The adhesive mayinitially be rolled out or covered, and then uncovered or rolled downonce the tube 3 is arranged at a desired position relative to thecannula 2. Other variants of the adhesive type and/or application withrespect to the surfaces of the tube 3 can also be used. For example, thetube 3 can adhere to the cannula through adhesives as discussed, or forexample, via elastic properties or an interference fit. In someembodiments, a shrink wrap or similar material may be utilized forcovering the desired openings 11 in cannula 2.

In operation, for example, after a procedure where a multi-stage cannulais utilized has been completed, a surgeon or other practitioner canattach the tube 3 over the cannula 2 through, for example, a puncture oraccess site through the heart wall, or alternatively, tube 3 can beattached upon removal of the cannula 2 from the patient's body. Theadhesive or other adhering means will hold the tube 3 in position on thecannula 2, generally to cover the central openings 11 corresponding tothe position of the right atrium, so that the modified cannula 2 canfunction as a bi-caval cannula during a subsequent procedure.

In the embodiment of FIGS. 9A-10, the elastic sheath or tube 3 can beapplied to currently existing multi-stage femoral venous cannula, and soadditional cannulae according to the invention may not need to beprovided. By covering the openings 11 along a central portion of thecannula 2, the cannula 2 can be converted from a multi-stage cannula toa bi-caval cannula, so long as openings 11 remain uncovered at both adistal end and a proximal end relative to the positioning of the tube 3.The kit including cannula 2 and tube 3 may also be advantageous in thattubing of different sizes, lengths, and/or configurations can beprovided, to provide a simple customizable cannula based on theparticular patient's anatomy.

The parts of the cannulae 1, 2 according to embodiments of the inventionare preferably made from one or more biocompatible materials, and mayall be made of the same material, or can be made of different materials.

Each of the embodiments discussed above provides a single cannula thatcan be converted from a multi-stage cannula to a bi-caval cannula ondemand, where a physician or other practitioner can close differentholes along the cannula to adjust the hole configurations of the cannulato suit the particular clinical application. In some embodiments, thecannula can further be converted from a bi-caval cannula to amulti-stage cannula as well, for example, by opening different holes,adding more flexibility for the physician.

Embodiments of the invention would provide a cannula that would allowfor customization of hole configurations, which could potentially reducethe number of products or product codes to stock. For example, cannulaeaccording to embodiments of the invention could replace both multi-stagecannula and bi-caval cannula, so that only a single type of cannulae canbe stocked to cover both types of applications. Embodiments of theinvention would also allow more flexibility with respect tocustomization based on surgeon preference and patient anatomy, forexample, different heart and/or vein sizes.

In addition, embodiments of the invention provide a more flexiblecannula that can be adjusted mid-procedure. Previously, in instanceswhere one of a multi-stage cannula or a bi-caval cannula is required fora first procedure, and then the other of the multi-stage cannula or thebi-caval cannula is required for a second procedure, upon completion ofthe first procedure, the first cannula had to be removed and the secondcannula then inserted and repositioned before the second procedure couldbe performed. With embodiments of the invention, a single cannula can bepositioned for the first procedure, and for example, adjusted to firstserve as a multi-stage cannula, and can then be converted for the secondprocedure, for example, to serve as a bi-caval cannula, while stillcorrectly positioned relative to the heart, so that removal andrepositioning of the cannula is no longer required, thereby reducingsurgical times and simplifying the surgical process. In addition, forexample, with the third embodiment discussed above, a conventionalmulti-stage cannula can still be used for a first procedure, and tubingof different lengths can be provided, where an appropriate sealing tubecan potentially be selected or cut mid-procedure, and then applied tothe cannula, to seal the desired number of openings on the cannula basedon the patient's anatomy, thereby providing a more customizable andeffective bi-caval cannula.

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatuses, and systems should not be construed aslimiting in any way. Instead, the present disclosure is directed towardall novel and nonobvious features and aspects of the various disclosedembodiments, alone and in various combinations and sub-combinations withone another. The methods, apparatuses, and systems are not limited toany specific aspect or feature or combination thereof, nor do thedisclosed embodiments require that any one or more specific advantagesbe present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage. For example, operations described sequentially can in somecases be rearranged or performed concurrently. Moreover, for the sake ofsimplicity, the attached figures may not show the various ways in whichthe disclosed methods can be used in conjunction with other methods.Additionally, the description sometimes uses terms like “provide” or“achieve” to describe the disclosed methods. These terms are high-levelabstractions of the actual operations that are performed. The actualoperations that correspond to these terms can vary depending on theparticular implementation and are readily discernible by one of ordinaryskill in the art.

In view of the many possible embodiments to which the principles of thedisclosure can be applied, it should be recognized that the illustratedembodiments are only preferred examples of the invention and should notbe taken as limiting the scope of the disclosure. Rather, the scope ofthe disclosure is defined by the following claims.

What is claimed is:
 1. A device for use in cardiopulmonary bypass, thedevice comprising a cannula configured to be positioned in at least oneof a right atrium, a superior vena cava, or an inferior vena cava of apatient, the cannula having a first end, a second end, and alongitudinal axis extending between the first end and the second end,the cannula comprising: a first section at the first end, the firstsection comprising an outer wall and having at least one openingtherethrough; a second section connected to the first section along thelongitudinal axis, the second section comprising an outer wall andhaving at least one opening therethrough; and a third section connectedto the second section along the longitudinal axis on a side of thesecond section opposite the first section, the third section comprisingan outer wall and having at least one opening therethrough; wherein in afirst configuration, the openings in each of the first section, thesecond section, and the third section are respectively open to innerspaces defined by the first section, the second section, and the thirdsection; and wherein in a second configuration, the at least one openingin the second section is occluded to restrict communication with theinner space defined by the second section, while the openings in thefirst section and the third section remain open to the inner spacesdefined by the first section and the third section, respectively.
 2. Thedevice of claim 1, wherein in the first configuration, the cannula isconfigured as a multi-stage femoral venous cannula.
 3. The device ofclaim 1, wherein in the second configuration, the cannula is configuredas a bi-caval femoral venous cannula.
 4. The device of claim 1, whereina material of the second section of the cannula is more rigid than amaterial of at least one of the first section of the cannula or thethird section of the cannula.
 5. The device of claim 1, wherein thecannula further comprises a wall movable relative to the second sectionbetween a first position wherein the device is in the firstconfiguration and the at least one opening in the second section of thecannula is open, and a second position wherein the device is in thesecond configuration and the at least one opening in the second sectionof the cannula is occluded by the wall.
 6. The device of claim 5,wherein the wall is positioned along an inner surface of the outer wallof the second section of the cannula.
 7. The device of claim 5, whereinthe wall rotates circumferentially around the longitudinal axis to movebetween the first position and the second position.
 8. The device ofclaim 5, wherein the wall moves laterally relative to the longitudinalaxis towards either the first end or the second end of the cannula tomove between the first position and the second position.
 9. The deviceof claim 5, wherein the wall comprises a plurality of wall segments. 10.The device of claim 1, further comprising a tubular cover configured tobe placed around the outer wall of the second section to occlude the atleast one opening in the second section when the device is in the secondconfiguration.
 11. The device of claim 10, wherein the cannula is amulti-stage cannula.
 12. The device of claim 10, wherein the cover isimpermeable to blood.
 13. The device of claim 10, wherein an adhesive onthe cover permanently adheres the cover to the second section of thecannula when the device is in the second configuration.
 14. The deviceof claim 10, wherein one cover is selected from a plurality of covershaving different sizes for placement around the outer wall of the secondsection of the cannula when the device is in the second configuration.15. A method for adjusting and positioning a femoral venous cannula in apatient for cardiopulmonary bypass during a cardiac procedure, thecannula having a first end, a second end, and a longitudinal axisextending between the first end and the second end, the cannulacomprising a first section at the first end and comprising an outer walland having at least one opening therethrough, a second section connectedto the first section along the longitudinal axis and comprising an outerwall and having at least one opening therethrough, and a third sectionconnected to the second section along the longitudinal axis on a side ofthe second section opposite the first section and comprising an outerwall and having at least one opening therethrough, wherein in a firstconfiguration, the openings in each of the first section, the secondsection, and the third section are respectively open to inner spacesdefined by the first section, the second section, and the third section,and wherein in a second configuration, the at least one opening in thesecond section is occluded to restrict communication with the innerspace defined by the second section, while the openings in the firstsection and the third section remain open to the inner spaces defined bythe first section and the third section, respectively, the methodcomprising: adjusting the cannula to one of the first configuration orthe second configuration; inserting the cannula through the femoral veinof the patient and advancing the cannula towards the heart of thepatient; and positioning the cannula at a first position in the patientwherein the at least one opening of the first section of the cannula isarranged in the superior vena cava, the at least one opening of thesecond section of the cannula is arranged in the right atrium, and theat least one opening of the third section of the cannula is arranged inthe inferior vena cava.
 16. The method of claim 15, wherein the cannulais adjusted to the first configuration when at least one of the leftatrium or the left ventricle of the heart of the patient is accessedduring the cardiac procedure.
 17. The method of claim 15, wherein thecannula is adjusted to the second configuration when at least one of theright atrium or the right ventricle of the heart of the patient isaccessed during the cardiac procedure.
 18. The method of claim 15,further comprising adjusting the cannula to the other one of the firstconfiguration or the second configuration when the cannula is at thefirst position in the patient.